The present invention relates to a microwave oven door and, more particularly, to a microwave oven door including a choke cavity for absorbing microwaves.
FIG. 1 shows a sectional view of a microwave oven including a door in a related art of the present invention. A heating chamber 3 is provided in an external casing 1 of a microwave oven, while a magentron 2 generating high frequency microwaves is provided on the upper part of the heating chamber 3. A foodstuff 5 to be heated by the microwaves is disposed in a food plate 4 on the inside bottom wall of the heating chamber 3.
FIG. 2 shows an enlarged sectional view of the microwave oven door assembly of FIG. 1. A door body 7 comprises a flange 7' forming a choke cavity 6 to absorb microwaves. The flange 7' surrounds a central opening at the central portion of the door body 7. The central opening of the door body 7 is sealed by a sealer plate 11 such as a thin hole punched metal plate, and a transparent plate 9 such as a glass plate for supporting the sealer plate 11 to form an inner door screen. An inner door plate 10 is connected to the door body 7 by a screw 12 through a component attach plate 8 connected to the door body 7. The sealer plate 11 and the transparent plate 9 are sandwiched by the component attach plate 8 and the inner door plate 10 to fix the sealer plate 11 and the transparent plate 9 to the door body 7. A choke cover 13 is detachably provided to cover an opening 6a of a choke cavity 6 which is formed by the door body 7 and the inner door plate 10. A front screen 14 is sandwiched by the door body 7 and a screen hold plate 16 both connected to the door body 7 by a screw 15 to secure the front screen 14 on the door body 7. A decoration board 17 is provided at the external peripery of the door body 7 to conceal the screen hold plate 16 and the screw 15 securing it.
In the door assembly as shown in FIG. 2, a number of components are required for the assembly, such as choke cover 13, component attach plate 8, decoration plate 17, and screws 12 and 15, thus requiring much labor during assembly, and making it difficult to reduce costs. Also, the outer surface of the microwave oven opposite to the heating chamber is not flat because the components form a noticeable concave or convex appearance, so that it is difficult to clean the inner side of the microwave oven door. It is desired that a novel microwave oven door be provided to be substantially flat and easily cleaned.